|Publication number||US5578084 A|
|Application number||US 08/211,269|
|Publication date||26 Nov 1996|
|Filing date||25 Sep 1992|
|Priority date||27 Sep 1991|
|Also published as||CA2119358A1, CA2119358C, DE69228397D1, DE69228397T2, EP0724819A1, EP0724819A4, EP0724819B1, WO1993006698A1|
|Publication number||08211269, 211269, PCT/1992/517, PCT/AU/1992/000517, PCT/AU/1992/00517, PCT/AU/92/000517, PCT/AU/92/00517, PCT/AU1992/000517, PCT/AU1992/00517, PCT/AU1992000517, PCT/AU199200517, PCT/AU92/000517, PCT/AU92/00517, PCT/AU92000517, PCT/AU9200517, US 5578084 A, US 5578084A, US-A-5578084, US5578084 A, US5578084A|
|Inventors||Janusz Kuzma, Henry L. Seldon, Gordon G. Brown|
|Original Assignee||Cochlear Ltd., University Of Melbourne|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (17), Non-Patent Citations (2), Referenced by (55), Classifications (9), Legal Events (6)|
|External Links: USPTO, USPTO Assignment, Espacenet|
This invention relates to electrode arrays for cochlear implants.
Electrode arrays for insertion into the cochlea are known in various forms in the prior art. They are generally manufactured in a straight form from a resilient material. When they are inserted into the cochlea, they flexibly curve into the spiral form of the scala tympani. However, the electrode array is resilient and hence tends to "remember" its straight form, and accordingly engages the outer (radially) wall of the scala tympani. For optimum electrical stimulation to occur, it is preferred that the electrodes engage the inner wall, near the modiolus.
One solution which has been proposed is to manufacture the electrode in a spiral shape. This type of arrangement is shown in U.S. Pat. No. 4,284,085 to Hansen et al, and in the device developed by the University of California at San Francisco. However, these devices are difficult to insert in a surgical procedure, and require specialised equipment and skills to approach satisfactory performance. Moreover, they use a curve for the array which is an estimate of average shape, not the actual shape of each patient's cochlea. These devices also require very careful manufacturing techniques to produce a reliable product.
It is accordingly an objective of the present invention to provide an electrode which combines the manufacturing and insertion advantages of the straight form of electrode, while providing engagement in use with the inner wall of the canal.
The present invention accordingly provides an electrode array which after insertion curves from its original substantially linear form into a curved shape. Preferably, the electrode array is constructed from a first portion which is flexible but stable which contains the electrodes, and a second portion which is formed from material which will expand after insertion so as to curve the overall electrode into a spiral shape. Preferably, this is achieved by utilising a material which expands slowly when in contact with water, so that over a period of hours or days after insertion the electrode slowly curves inwardly so as to engage the inner wall of the canal. Hence, the optimal stimulation arrangement whereby the electrodes engage the inner wall of the canal is likely to be achieved.
One embodiment of the invention will now be described with reference to the accompanying figures, in which:
FIG. 1 is a schematic cross-sectional illustration through the plane of the cochlea showing insertion of the electrode;
FIGS. 2 and 3 are crosssectional views along line A--A of alternative constructions of the electrode array;
FIG. 4 is a similar view to FIG. 1 showing the positional change of the electrode array after curving;
FIG. 5 is a lateral section across FIG. 4;
FIG. 6 shows the preferred mechanical properties required of the electrode array according to the present invention;
FIG. 7 is a detailed illustration of one construction of the electrode array according to the present invention;
FIG. 8 is a detailed illustration of another construction of the electrode array according to the present invention; and
FIG. 9 shows one method for electrically connecting the electrodes according to the embodiment of FIG. 8.
One embodiment of the invention will now be described, however, it is noted that the present invention is of wide scope and that many possible embodiments fall within the general inventive concept.
Referring to FIG. 1, the electrode array 12 is initially preferably formed in a generally straight cylindrical or semi-cylindrical shape. The materials are selected such that this shape will generally be maintained outside of the human body at normal conditions of temperature and humidity. In this form, it is relatively simple to control the insertion of the electrode into the cochlea 30. It will be appreciated that the illustration of the cochlea is purely schematic and is not intended to be anatomically accurate. Immediately after insertion, the electrode generally rests against the radially outer wall of the scala tympani 31, as can be seen in FIGS. 4 and 5, at position 1.
The electrode is preferably constructed in essentially two layers. Referring to FIGS. 2 and 3, the first layer (10, 20) is formed from a suitable bio-compatible material, such as a silicone polymer, and contains the electrode contacts and connecting leads in the form of a long strip structure. It is preferably constructed from a material which is flexible for bending in at least one direction, and stable in its dimensions both outside and inside the living body. In this fashion, the correct spacings between electrodes can be maintained, and the proper electrical functioning predicted accurately in use.
The second layer (11, 21) is formed from a bio-compatible material which is adhered, co-extruded or moulded to the first layer. This material has the important property of a controlled rate of expansion when exposed to the water contained in body fluids.
Any suitable water-expanding material which fulfils the above criteria may be utilised in the invention. A suitable material may be a polymer which swells in response to contact with a fluid such as water. A first preferred material is Silastic A (Trade Mark) silicone polymer mixed with a certain amount of finely ground NaCl. The exact proportion of NaCl depends on the geometry chosen and can be readily determined by those skilled in the art. A second preferred material is Silastic A mixed with polyacrylic acid to form a hygroscopic layer in the electrode structure. Both these materials will slowly expand in contact with water, thereby deforming the electrode structure from its original straight shape to a generally spiral shape with a curvature equal to or smaller than the scala tympani 31.
It will be appreciated that in its broadest form the invention encompasses alteration of shape in situ by any means, including polymers or other materials which alter their volume in response to other stimuli, such as heat or electrical stimuli, or materials which merely alter their shape so as to deform the array. It is the post insertion curving which is at the core of the present invention.
Thus, after a suitable period of time, typically hours or days, the electrode array 12 gradually moves into substantially position 2 shown in FIGS. 4 and 5. The electrodes are always positioned on their correct side because of the expansion geometry involved, so that they are in close proximity to the modiolus. It will be appreciated that the insertion is a surgical procedure and so will not always result in theoretical results, owing to differences in human anatomy, the skill and experience of the surgeon, and other factors.
FIG. 7 illustrates one structure incorporating the features of the present invention. A first layer 10 is constructed from a mechanically stable and bio-compatible polymer strip, with metal electrodes 13 deposited on one side and leads 14 on the other side. Any suitable material may be used for the first layer 10, although polyamide foil is preferred. The electrodes 13 and leads 14 may be formed from any suitable material, for instance sputtered platinum.
The other side of the electrode is formed from a generally semi-cylindrical portion 11 of water absorbing polymer. Preferably, the strip 10 is adhered to the material 11 during the moulding process.
FIG. 8 illustrates an alternative embodiment of the inventive structure. The first layer 20 is formed from a number of wires 23 placed side by side to form a flat ribbon connected to the platinum disk electrodes 22. This complete structure 20 is then moulded into the water absorbing polymer 21. FIG. 9 shows the connection of the discs 22 by lead wires 23.
The electrode is preferably formed with mechanical characteristics as shown in FIG. 6. The electrode (in its straight form) should be flexible in a direction which is perpendicular to the plane of the electrodes, or in other words in the radial direction in the inserted structure, shown in FIG. 6 as direction D. It should, however, be stable along the plane of the electrodes, and relatively stiff across the plane of the electrodes, or in other words in directions perpendicular to the radial and coming out of the page in the illustration of FIG. 6, shown as directions B and C.
It will be appreciated that suitable polymer selection and the exact volumes of the various portions of the array will enable a suitable degree of curvature to be provided. Other differential expansion or contraction mechanisms using the same or other material properties, or other arrangements of water expanding polymer, for instance in shaped sections, are encompassed within the present invention. The array need not be precisely straight when manufactured--it may incorporate a small curve at the end to aid insertion. It will also be appreciated that embodiments are possible which do not have uniform characteristics at all points in the array.
It will be appreciated that the present invention relates to a principle of general application and the particular embodiments disclosed herein are not to be considered as limitative. Variations and additions will be apparent to those skilled in the art and are encompassed within the general scope of the invention.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US3751605 *||4 Feb 1972||7 Aug 1973||Beckman Instruments Inc||Method for inducing hearing|
|US3752939 *||4 Feb 1972||14 Aug 1973||Beckman Instruments Inc||Prosthetic device for the deaf|
|US4284085 *||13 Nov 1978||18 Aug 1981||Hansen Carl C||Electrode for implantation into the cochlea (II)|
|US4400590 *||22 Dec 1980||23 Aug 1983||The Regents Of The University Of California||Apparatus for multichannel cochlear implant hearing aid system|
|US4484987 *||19 May 1983||27 Nov 1984||The Regents Of The University Of California||Method and membrane applicable to implantable sensor|
|US4762135 *||15 Nov 1985||9 Aug 1988||Puije P D V D||Cochlea implant|
|US4819647 *||9 Feb 1988||11 Apr 1989||The Regents Of The University Of California||Intracochlear electrode array|
|US4832051 *||27 Jun 1986||23 May 1989||Symbion, Inc.||Multiple-electrode intracochlear device|
|US4898183 *||20 Jun 1989||6 Feb 1990||Cochlear Pty. Limited||Apparatus and method for insertion of cochlear electrode assembly|
|US5000194 *||25 Aug 1988||19 Mar 1991||Cochlear Corporation||Array of bipolar electrodes|
|US5037497 *||19 Jul 1990||6 Aug 1991||Cochlear Corporation||Method of fabricating an array of recessed radially oriented bipolar electrodes|
|*||DE2823798A||Title not available|
|EP0002068A2 *||21 Nov 1978||30 May 1979||Carl Christian Hansen||Electrode for implantation into cochlea|
|EP0007157A2 *||1 May 1979||23 Jan 1980||The University Of Melbourne||Improved electrode array and method of making the same|
|EP0124930A1 *||9 Apr 1984||14 Nov 1984||The Commonwealth Of Australia||Cochlear implant system for an auditory prosthesis|
|EP0247649A1 *||9 Apr 1984||2 Dec 1987||The Commonwealth Of Australia||Cochlear implant prosthesis current switching and power supply|
|FR2441381A1 *||Title not available|
|1||Guyton, David; "Science", vol. 131, Jul. 1973.|
|2||*||Guyton, David; Science , vol. 131, Jul. 1973.|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US5876443 *||26 Feb 1997||2 Mar 1999||Med-El Elektromedizinisch Gerate Ges.M.B.H.||Structure, method of use, and method of manufacture of an implanted hearing prosthesis|
|US6038484 *||26 Aug 1998||14 Mar 2000||Advanced Bionics Corporation||Cochlear electrode with modiolar-hugging system including a flexible positioner|
|US6070105 *||26 Aug 1998||30 May 2000||Advanced Bionics Corporation||Modiolus-hugging cochlear electrodes|
|US6074422 *||22 Apr 1998||13 Jun 2000||Epic Biosonics Inc.||Inner ear implant device|
|US6078841 *||18 Dec 1998||20 Jun 2000||Advanced Bionics Corporation||Flexible positioner for use with implantable cochlear electrode array|
|US6119044 *||1 Mar 1999||12 Sep 2000||Advanced Bionics Corporation||Cochlear electrode array with positioning stylet|
|US6125302 *||26 Aug 1998||26 Sep 2000||Advanced Bionics Corporation||Precurved modiolar-hugging cochlear electrode|
|US6129753 *||9 Feb 1999||10 Oct 2000||Advanced Bionics Corporation||Cochlear electrode array with electrode contacts on medial side|
|US6144883 *||2 Jul 1999||7 Nov 2000||Advanced Bionics Corporation||Method of making a cochlear electrode array with electrode contacts on medial side|
|US6149657 *||18 May 1999||21 Nov 2000||Advanced Bionics Corporation||Insertion tool for placement of a flexible silicone mold or positioner within a cochlea|
|US6151526 *||27 Apr 1999||21 Nov 2000||Advanced Bionics Corporation||Ribbed electrode for cochlear stimulation|
|US6266568||27 Apr 1999||24 Jul 2001||Advanced Bionics Corporation||Inflatable cochlear electrode array and method of making same|
|US6304787||17 Aug 1999||16 Oct 2001||Advanced Bionics Corporation||Cochlear electrode array having current-focusing and tissue-treating features|
|US6306168||4 May 1998||23 Oct 2001||Epic Biosonics Inc.||Means for implanting a device in the canalis cochlearis|
|US6321125||19 Nov 1999||20 Nov 2001||Advanced Bionics Corporation||Cochlear electrode system including distally attached flexible positioner|
|US6358281 *||29 Nov 1999||19 Mar 2002||Epic Biosonics Inc.||Totally implantable cochlear prosthesis|
|US6374143||18 Aug 1999||16 Apr 2002||Epic Biosonics, Inc.||Modiolar hugging electrode array|
|US6487453||1 Jun 2000||26 Nov 2002||Advanced Bionics Corporation||Electrode system for ossified cochlea|
|US6565503||13 Apr 2001||20 May 2003||Cochlear Limited||At least partially implantable system for rehabilitation of hearing disorder|
|US6604283||3 Mar 2000||12 Aug 2003||Advanced Bionics Corporation||Method of making precurved, modiolar-hugging cochlear electrode|
|US6697674||13 Apr 2001||24 Feb 2004||Cochlear Limited||At least partially implantable system for rehabilitation of a hearing disorder|
|US6736770||27 Aug 2001||18 May 2004||Cochlear Limited||Implantable medical device comprising an hermetically sealed housing|
|US6968238||5 Aug 2003||22 Nov 2005||Kuzma Janusz A||Method for inserting cochlear electrode and insertion tool for use therewith|
|US7315763||19 Sep 2003||1 Jan 2008||Advanced Bionics Corporation||Cochlear implant electrode and method of making same|
|US7319906||28 May 2004||15 Jan 2008||Advanced Bionics Corporation||Cochlear implant electrode and method of making same|
|US7367992 *||11 Mar 2002||6 May 2008||Cochlear Limited||Curved cochlear implant electrode array|
|US7376563||2 Jul 2001||20 May 2008||Cochlear Limited||System for rehabilitation of a hearing disorder|
|US7406352||12 Mar 2002||29 Jul 2008||Cochlear Limited||Laminated electrode for a cochlear implant|
|US7451000||28 Nov 2001||11 Nov 2008||Cochlear Limited||Pre-curved cochlear implant electrode array|
|US7941228||10 Oct 2007||10 May 2011||Advanced Bionics, Llc||Cochlear implant electrode and method of making same|
|US7949412||1 Jun 2006||24 May 2011||Advanced Bionics, Llc||Coated electrode array having uncoated electrode contacts|
|US7974712||13 Oct 2008||5 Jul 2011||Cochlear Limited||Pre-curved cochlear implant electrode array|
|US8046081||18 May 2006||25 Oct 2011||Med-El Elektromedizinische Geraete Gmbh||Implanted system with DC free inputs and outputs|
|US8145326 *||5 Nov 2007||27 Mar 2012||Med-El Elektromedizinische Geraete Gmbh||Intra-cochlear electrode with a partially detachable hydrophilic segment for deferred self-positioning|
|US8190271||29 Aug 2008||29 May 2012||Advanced Bionics, Llc||Minimizing trauma during and after insertion of a cochlear lead|
|US8271101||31 Jul 2009||18 Sep 2012||Advanced Bionics||Modular drug delivery system for minimizing trauma during and after insertion of a cochlear lead|
|US8554330||2 Sep 2009||8 Oct 2013||The University Of Queensland||Cochlear implants|
|US8620459||3 Jul 2011||31 Dec 2013||Cochlear Limited||Pre-curved cochlear implant electrode array|
|US8792999||25 Jan 2012||29 Jul 2014||Cochlear Limited||Implantable tissue stimulating electrode assembly|
|US8805546||7 Sep 2005||12 Aug 2014||Hearworks Pty, Ltd||Cochlear electrode with precurved and straight sections|
|US9044588||13 Apr 2010||2 Jun 2015||Cochlear Limited||Reference electrode apparatus and method for neurostimulation implants|
|US20020012438 *||2 Jul 2001||31 Jan 2002||Hans Leysieffer||System for rehabilitation of a hearing disorder|
|US20020051550 *||27 Aug 2001||2 May 2002||Hans Leysieffer||Implantable hermetically sealed housing for an implantable medical device and process for producing the same|
|US20040116995 *||11 Mar 2002||17 Jun 2004||Fysh Dadd||Curved cochlear implant electrode array|
|US20040127968 *||19 Sep 2003||1 Jul 2004||Kuzma Janusz A.||Cochlear implant electrode and method of making same|
|US20040172102 *||30 Dec 2003||2 Sep 2004||Cochlear Limited||At least partially implantable system for rehabilitation of a hearing disorder|
|US20040172118 *||12 Mar 2002||2 Sep 2004||Peter Gibson||Laminated electrode for a cochlear implant|
|US20040220651 *||28 May 2004||4 Nov 2004||Kuzma Janusz A||Cochlear implant electrode and method of making same|
|US20130184804 *||22 Jan 2008||18 Jul 2013||Cochlear Limited||Implantable component interface|
|EP1145734A2||12 Apr 2001||17 Oct 2001||IMPLEX Aktiengesellschaft Hearing Technology||At least partially implantable system for the rehabilitation of a hearing disorder|
|EP1604626A2||21 May 1999||14 Dec 2005||Cochlear Limited||A cochlear implant electrode array|
|EP2042137A1||21 May 1999||1 Apr 2009||Cochlear Limited||A cochlear implant electrode array|
|WO1998052643A1 *||19 May 1998||26 Nov 1998||Bioelectric Corp||Cochlear implant with shape memory material and method for implanting the same|
|WO2002043623A1 *||28 Nov 2001||6 Jun 2002||Cochlear Ltd||Pre-curved cochlear implant electrode array|
|WO2013111096A1 *||24 Jan 2013||1 Aug 2013||Cochlear Limited||Tissue stimulating electrode assembly|
|U.S. Classification||623/10, 607/137|
|International Classification||A61F2/18, A61N1/05, A61F11/04, H04R25/00|
|European Classification||A61N1/05K2, A61F11/04|
|4 May 1994||AS||Assignment|
Owner name: COCHLEAR PTY. LIMITED, AUSTRALIA
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KUZMA, JANUSZ;SELDON, HENRY LEE;BROWN, GORDON G.;REEL/FRAME:007100/0131;SIGNING DATES FROM 19940315 TO 19940323
Owner name: UNIVERSITY OF MELBOURNE, THE, AUSTRALIA
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KUZMA, JANUSZ;SELDON, HENRY LEE;BROWN, GORDON G.;REEL/FRAME:007100/0131;SIGNING DATES FROM 19940315 TO 19940323
|25 Jul 1996||AS||Assignment|
Owner name: COCHLEAR LIMITED, AUSTRALIA
Free format text: CHANGE OF NAME;ASSIGNOR:COCHLEAR PTY. LTD.;REEL/FRAME:008048/0193
Effective date: 19951009
|23 May 2000||FPAY||Fee payment|
Year of fee payment: 4
|25 May 2004||FPAY||Fee payment|
Year of fee payment: 8
|30 May 2008||FPAY||Fee payment|
Year of fee payment: 12
|30 May 2008||SULP||Surcharge for late payment|
Year of fee payment: 11